Origin of Nonideal Graphene-Silicon Schottky Junction

In this paper, we investigate the origin of the nonideal turn- ON characteristics of the graphene-silicon Schottky junction. Native oxide (SiO2) is proved to play a critical role in determining the behavior of a graphene-Si junction. Within the metal-oxide-semiconductor structure, the effective voltage drop across the junction degrades due to the capacitor network, which contributes to an increased ideality factor. Residual metal catalysts are detected, which act as recombination centers in the silicon and further degrade the ideality factor by enhancing the recombination current. The recombination current is found to be the dominant factor in making the junction nonideal. Forming gas annealing and the insertion of an interfacial dielectric restore the ideality of a graphene-Si junction by reducing the interface states and bulk recombination centers.